Tilman Kispersky wrote:
I have python code in a class method translated from C++ that looks
sort of like this:
self.dydt[1] = self.a * (self.b * self.y[0] - self.y[1])
To make this more readable in C++ I had made macros to achieve this:
#define du (dydt[1])
#define u (y[1])
#define V (y[0])
du = a * (b * V - u);
I realize the value of not having macros in Python. They've tripped
me up more than once in C++. My question is:
Is there any way to write a shorterhand more readable version of the
python code above? I'm doing several calculations one after the other
and some of the lines are quite long.
Names in Python point to objects so you can bind several names to the same
location.
>>>> self.dydt[1] = self.a * (self.b * self.y[0] - self.y[1])
The following will work.
a = self.a
b = self.b
u = self.y[0]
V = self.y[1]
self.dytd[1] = a * (b * V - u)
In addition to making the lines shorter, I'm pretty sure they will be slightly
faster because lookups on the local variables is slightly faster than on the
instance variables (self.?).
Note: I think your parenthesis are incorrect in the equation above. If they
aren't then no parenthesis are necessary since multiplication takes precedence
over subtraction.
Hope this helps.
-Larry
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